2 * sja1000.c - Philips SJA1000 network device driver
4 * Copyright (c) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33,
5 * 38106 Braunschweig, GERMANY
7 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of Volkswagen nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * Alternatively, provided that this notice is retained in full, this
23 * software may be distributed under the terms of the GNU General
24 * Public License ("GPL") version 2, in which case the provisions of the
25 * GPL apply INSTEAD OF those given above.
27 * The provided data structures and external interfaces from this code
28 * are not restricted to be used by modules with a GPL compatible license.
30 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
31 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
32 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
33 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
34 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
36 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
40 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
45 #include <linux/module.h>
46 #include <linux/init.h>
47 #include <linux/kernel.h>
48 #include <linux/sched.h>
49 #include <linux/types.h>
50 #include <linux/fcntl.h>
51 #include <linux/interrupt.h>
52 #include <linux/ptrace.h>
53 #include <linux/string.h>
54 #include <linux/errno.h>
55 #include <linux/netdevice.h>
56 #include <linux/if_arp.h>
57 #include <linux/if_ether.h>
58 #include <linux/skbuff.h>
59 #include <linux/delay.h>
61 #include <linux/can/dev.h>
62 #include <linux/can/error.h>
63 #include <linux/can/led.h>
67 #define DRV_NAME "sja1000"
69 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
70 MODULE_LICENSE("Dual BSD/GPL");
71 MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");
73 static const struct can_bittiming_const sja1000_bittiming_const = {
85 static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val)
90 * The command register needs some locking and time to settle
91 * the write_reg() operation - especially on SMP systems.
93 spin_lock_irqsave(&priv->cmdreg_lock, flags);
94 priv->write_reg(priv, SJA1000_CMR, val);
95 priv->read_reg(priv, SJA1000_SR);
96 spin_unlock_irqrestore(&priv->cmdreg_lock, flags);
99 static int sja1000_is_absent(struct sja1000_priv *priv)
101 return (priv->read_reg(priv, SJA1000_MOD) == 0xFF);
104 static int sja1000_probe_chip(struct net_device *dev)
106 struct sja1000_priv *priv = netdev_priv(dev);
108 if (priv->reg_base && sja1000_is_absent(priv)) {
109 printk(KERN_INFO "%s: probing @0x%lX failed\n",
110 DRV_NAME, dev->base_addr);
116 static void set_reset_mode(struct net_device *dev)
118 struct sja1000_priv *priv = netdev_priv(dev);
119 unsigned char status = priv->read_reg(priv, SJA1000_MOD);
122 /* disable interrupts */
123 priv->write_reg(priv, SJA1000_IER, IRQ_OFF);
125 for (i = 0; i < 100; i++) {
126 /* check reset bit */
127 if (status & MOD_RM) {
128 priv->can.state = CAN_STATE_STOPPED;
133 priv->write_reg(priv, SJA1000_MOD, MOD_RM);
135 status = priv->read_reg(priv, SJA1000_MOD);
138 netdev_err(dev, "setting SJA1000 into reset mode failed!\n");
141 static void set_normal_mode(struct net_device *dev)
143 struct sja1000_priv *priv = netdev_priv(dev);
144 unsigned char status = priv->read_reg(priv, SJA1000_MOD);
147 for (i = 0; i < 100; i++) {
148 /* check reset bit */
149 if ((status & MOD_RM) == 0) {
150 priv->can.state = CAN_STATE_ERROR_ACTIVE;
151 /* enable interrupts */
152 if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
153 priv->write_reg(priv, SJA1000_IER, IRQ_ALL);
155 priv->write_reg(priv, SJA1000_IER,
160 /* set chip to normal mode */
161 if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
162 priv->write_reg(priv, SJA1000_MOD, MOD_LOM);
164 priv->write_reg(priv, SJA1000_MOD, 0x00);
168 status = priv->read_reg(priv, SJA1000_MOD);
171 netdev_err(dev, "setting SJA1000 into normal mode failed!\n");
174 static void sja1000_start(struct net_device *dev)
176 struct sja1000_priv *priv = netdev_priv(dev);
178 /* leave reset mode */
179 if (priv->can.state != CAN_STATE_STOPPED)
182 /* Clear error counters and error code capture */
183 priv->write_reg(priv, SJA1000_TXERR, 0x0);
184 priv->write_reg(priv, SJA1000_RXERR, 0x0);
185 priv->read_reg(priv, SJA1000_ECC);
187 /* leave reset mode */
188 set_normal_mode(dev);
191 static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
196 if (netif_queue_stopped(dev))
197 netif_wake_queue(dev);
207 static int sja1000_set_bittiming(struct net_device *dev)
209 struct sja1000_priv *priv = netdev_priv(dev);
210 struct can_bittiming *bt = &priv->can.bittiming;
213 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
214 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
215 (((bt->phase_seg2 - 1) & 0x7) << 4);
216 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
219 netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
221 priv->write_reg(priv, SJA1000_BTR0, btr0);
222 priv->write_reg(priv, SJA1000_BTR1, btr1);
227 static int sja1000_get_berr_counter(const struct net_device *dev,
228 struct can_berr_counter *bec)
230 struct sja1000_priv *priv = netdev_priv(dev);
232 bec->txerr = priv->read_reg(priv, SJA1000_TXERR);
233 bec->rxerr = priv->read_reg(priv, SJA1000_RXERR);
239 * initialize SJA1000 chip:
243 * - enable interrupts
244 * - start operating mode
246 static void chipset_init(struct net_device *dev)
248 struct sja1000_priv *priv = netdev_priv(dev);
250 /* set clock divider and output control register */
251 priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
253 /* set acceptance filter (accept all) */
254 priv->write_reg(priv, SJA1000_ACCC0, 0x00);
255 priv->write_reg(priv, SJA1000_ACCC1, 0x00);
256 priv->write_reg(priv, SJA1000_ACCC2, 0x00);
257 priv->write_reg(priv, SJA1000_ACCC3, 0x00);
259 priv->write_reg(priv, SJA1000_ACCM0, 0xFF);
260 priv->write_reg(priv, SJA1000_ACCM1, 0xFF);
261 priv->write_reg(priv, SJA1000_ACCM2, 0xFF);
262 priv->write_reg(priv, SJA1000_ACCM3, 0xFF);
264 priv->write_reg(priv, SJA1000_OCR, priv->ocr | OCR_MODE_NORMAL);
268 * transmit a CAN message
269 * message layout in the sk_buff should be like this:
270 * xx xx xx xx ff ll 00 11 22 33 44 55 66 77
271 * [ can-id ] [flags] [len] [can data (up to 8 bytes]
273 static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
274 struct net_device *dev)
276 struct sja1000_priv *priv = netdev_priv(dev);
277 struct can_frame *cf = (struct can_frame *)skb->data;
284 if (can_dropped_invalid_skb(dev, skb))
287 netif_stop_queue(dev);
289 fi = dlc = cf->can_dlc;
292 if (id & CAN_RTR_FLAG)
293 fi |= SJA1000_FI_RTR;
295 if (id & CAN_EFF_FLAG) {
297 dreg = SJA1000_EFF_BUF;
298 priv->write_reg(priv, SJA1000_FI, fi);
299 priv->write_reg(priv, SJA1000_ID1, (id & 0x1fe00000) >> 21);
300 priv->write_reg(priv, SJA1000_ID2, (id & 0x001fe000) >> 13);
301 priv->write_reg(priv, SJA1000_ID3, (id & 0x00001fe0) >> 5);
302 priv->write_reg(priv, SJA1000_ID4, (id & 0x0000001f) << 3);
304 dreg = SJA1000_SFF_BUF;
305 priv->write_reg(priv, SJA1000_FI, fi);
306 priv->write_reg(priv, SJA1000_ID1, (id & 0x000007f8) >> 3);
307 priv->write_reg(priv, SJA1000_ID2, (id & 0x00000007) << 5);
310 for (i = 0; i < dlc; i++)
311 priv->write_reg(priv, dreg++, cf->data[i]);
313 can_put_echo_skb(skb, dev, 0);
315 if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
316 sja1000_write_cmdreg(priv, CMD_TR | CMD_AT);
318 sja1000_write_cmdreg(priv, CMD_TR);
323 static void sja1000_rx(struct net_device *dev)
325 struct sja1000_priv *priv = netdev_priv(dev);
326 struct net_device_stats *stats = &dev->stats;
327 struct can_frame *cf;
334 /* create zero'ed CAN frame buffer */
335 skb = alloc_can_skb(dev, &cf);
339 fi = priv->read_reg(priv, SJA1000_FI);
341 if (fi & SJA1000_FI_FF) {
342 /* extended frame format (EFF) */
343 dreg = SJA1000_EFF_BUF;
344 id = (priv->read_reg(priv, SJA1000_ID1) << 21)
345 | (priv->read_reg(priv, SJA1000_ID2) << 13)
346 | (priv->read_reg(priv, SJA1000_ID3) << 5)
347 | (priv->read_reg(priv, SJA1000_ID4) >> 3);
350 /* standard frame format (SFF) */
351 dreg = SJA1000_SFF_BUF;
352 id = (priv->read_reg(priv, SJA1000_ID1) << 3)
353 | (priv->read_reg(priv, SJA1000_ID2) >> 5);
356 cf->can_dlc = get_can_dlc(fi & 0x0F);
357 if (fi & SJA1000_FI_RTR) {
360 for (i = 0; i < cf->can_dlc; i++)
361 cf->data[i] = priv->read_reg(priv, dreg++);
366 /* release receive buffer */
367 sja1000_write_cmdreg(priv, CMD_RRB);
372 stats->rx_bytes += cf->can_dlc;
374 can_led_event(dev, CAN_LED_EVENT_RX);
377 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
379 struct sja1000_priv *priv = netdev_priv(dev);
380 struct net_device_stats *stats = &dev->stats;
381 struct can_frame *cf;
383 enum can_state state = priv->can.state;
386 skb = alloc_can_err_skb(dev, &cf);
390 if (isrc & IRQ_DOI) {
391 /* data overrun interrupt */
392 netdev_dbg(dev, "data overrun interrupt\n");
393 cf->can_id |= CAN_ERR_CRTL;
394 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
395 stats->rx_over_errors++;
397 sja1000_write_cmdreg(priv, CMD_CDO); /* clear bit */
401 /* error warning interrupt */
402 netdev_dbg(dev, "error warning interrupt\n");
404 if (status & SR_BS) {
405 state = CAN_STATE_BUS_OFF;
406 cf->can_id |= CAN_ERR_BUSOFF;
408 } else if (status & SR_ES) {
409 state = CAN_STATE_ERROR_WARNING;
411 state = CAN_STATE_ERROR_ACTIVE;
413 if (isrc & IRQ_BEI) {
414 /* bus error interrupt */
415 priv->can.can_stats.bus_error++;
418 ecc = priv->read_reg(priv, SJA1000_ECC);
420 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
422 switch (ecc & ECC_MASK) {
424 cf->data[2] |= CAN_ERR_PROT_BIT;
427 cf->data[2] |= CAN_ERR_PROT_FORM;
430 cf->data[2] |= CAN_ERR_PROT_STUFF;
433 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
434 cf->data[3] = ecc & ECC_SEG;
437 /* Error occurred during transmission? */
438 if ((ecc & ECC_DIR) == 0)
439 cf->data[2] |= CAN_ERR_PROT_TX;
441 if (isrc & IRQ_EPI) {
442 /* error passive interrupt */
443 netdev_dbg(dev, "error passive interrupt\n");
445 state = CAN_STATE_ERROR_PASSIVE;
447 state = CAN_STATE_ERROR_ACTIVE;
449 if (isrc & IRQ_ALI) {
450 /* arbitration lost interrupt */
451 netdev_dbg(dev, "arbitration lost interrupt\n");
452 alc = priv->read_reg(priv, SJA1000_ALC);
453 priv->can.can_stats.arbitration_lost++;
455 cf->can_id |= CAN_ERR_LOSTARB;
456 cf->data[0] = alc & 0x1f;
459 if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
460 state == CAN_STATE_ERROR_PASSIVE)) {
461 uint8_t rxerr = priv->read_reg(priv, SJA1000_RXERR);
462 uint8_t txerr = priv->read_reg(priv, SJA1000_TXERR);
463 cf->can_id |= CAN_ERR_CRTL;
464 if (state == CAN_STATE_ERROR_WARNING) {
465 priv->can.can_stats.error_warning++;
466 cf->data[1] = (txerr > rxerr) ?
467 CAN_ERR_CRTL_TX_WARNING :
468 CAN_ERR_CRTL_RX_WARNING;
470 priv->can.can_stats.error_passive++;
471 cf->data[1] = (txerr > rxerr) ?
472 CAN_ERR_CRTL_TX_PASSIVE :
473 CAN_ERR_CRTL_RX_PASSIVE;
479 priv->can.state = state;
484 stats->rx_bytes += cf->can_dlc;
489 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
491 struct net_device *dev = (struct net_device *)dev_id;
492 struct sja1000_priv *priv = netdev_priv(dev);
493 struct net_device_stats *stats = &dev->stats;
494 uint8_t isrc, status;
500 /* Shared interrupts and IRQ off? */
501 if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF)
504 while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
505 (n < SJA1000_MAX_IRQ)) {
507 status = priv->read_reg(priv, SJA1000_SR);
508 /* check for absent controller due to hw unplug */
509 if (status == 0xFF && sja1000_is_absent(priv))
513 netdev_warn(dev, "wakeup interrupt\n");
516 /* transmission buffer released */
517 if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
518 !(status & SR_TCS)) {
520 can_free_echo_skb(dev, 0);
522 /* transmission complete */
524 priv->read_reg(priv, SJA1000_FI) & 0xf;
526 can_get_echo_skb(dev, 0);
528 netif_wake_queue(dev);
529 can_led_event(dev, CAN_LED_EVENT_TX);
532 /* receive interrupt */
533 while (status & SR_RBS) {
535 status = priv->read_reg(priv, SJA1000_SR);
536 /* check for absent controller */
537 if (status == 0xFF && sja1000_is_absent(priv))
541 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
542 /* error interrupt */
543 if (sja1000_err(dev, isrc, status))
550 priv->post_irq(priv);
552 if (n >= SJA1000_MAX_IRQ)
553 netdev_dbg(dev, "%d messages handled in ISR", n);
555 return (n) ? IRQ_HANDLED : IRQ_NONE;
557 EXPORT_SYMBOL_GPL(sja1000_interrupt);
559 static int sja1000_open(struct net_device *dev)
561 struct sja1000_priv *priv = netdev_priv(dev);
564 /* set chip into reset mode */
568 err = open_candev(dev);
572 /* register interrupt handler, if not done by the device driver */
573 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
574 err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
575 dev->name, (void *)dev);
582 /* init and start chi */
585 can_led_event(dev, CAN_LED_EVENT_OPEN);
587 netif_start_queue(dev);
592 static int sja1000_close(struct net_device *dev)
594 struct sja1000_priv *priv = netdev_priv(dev);
596 netif_stop_queue(dev);
599 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
600 free_irq(dev->irq, (void *)dev);
604 can_led_event(dev, CAN_LED_EVENT_STOP);
609 struct net_device *alloc_sja1000dev(int sizeof_priv)
611 struct net_device *dev;
612 struct sja1000_priv *priv;
614 dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
615 SJA1000_ECHO_SKB_MAX);
619 priv = netdev_priv(dev);
622 priv->can.bittiming_const = &sja1000_bittiming_const;
623 priv->can.do_set_bittiming = sja1000_set_bittiming;
624 priv->can.do_set_mode = sja1000_set_mode;
625 priv->can.do_get_berr_counter = sja1000_get_berr_counter;
626 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
627 CAN_CTRLMODE_BERR_REPORTING | CAN_CTRLMODE_LISTENONLY |
628 CAN_CTRLMODE_ONE_SHOT;
630 spin_lock_init(&priv->cmdreg_lock);
633 priv->priv = (void *)priv + sizeof(struct sja1000_priv);
637 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
639 void free_sja1000dev(struct net_device *dev)
643 EXPORT_SYMBOL_GPL(free_sja1000dev);
645 static const struct net_device_ops sja1000_netdev_ops = {
646 .ndo_open = sja1000_open,
647 .ndo_stop = sja1000_close,
648 .ndo_start_xmit = sja1000_start_xmit,
651 int register_sja1000dev(struct net_device *dev)
655 if (!sja1000_probe_chip(dev))
658 dev->flags |= IFF_ECHO; /* we support local echo */
659 dev->netdev_ops = &sja1000_netdev_ops;
664 ret = register_candev(dev);
667 devm_can_led_init(dev);
671 EXPORT_SYMBOL_GPL(register_sja1000dev);
673 void unregister_sja1000dev(struct net_device *dev)
676 unregister_candev(dev);
678 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
680 static __init int sja1000_init(void)
682 printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
687 module_init(sja1000_init);
689 static __exit void sja1000_exit(void)
691 printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
694 module_exit(sja1000_exit);